[partition] In logging, name device nicely

- Provide a convenience method that names a Partition* with the
   best human-readable name we can find (worst-case, spit out a
   pointer representation which will at least help figure out
   the identity of the Partition*).

src/modules/partition/core/PartUtils.cpp

@@ -42,6 +42,25 @@
 namespace PartUtils
 {
 
+static QString
+convenienceName( const Partition* const candidate )
+{
+    if ( !candidate->mountPoint().isEmpty() )
+        return candidate->mountPoint();
+    if ( !candidate->partitionPath().isEmpty() )
+        return candidate->partitionPath();
+    if ( !candidate->devicePath().isEmpty() )
+        return candidate->devicePath();
+    if ( !candidate->deviceNode().isEmpty() )
+        return candidate->devicePath();
+
+    QString p;
+    QTextStream s( &p );
+    s << (void *)candidate;
+
+    return p;
+}
+
 bool
 canBeReplaced( Partition* candidate )
 {
@@ -63,12 +82,12 @@ canBeReplaced( Partition* candidate )
              << QString( "(%1GB)" ).arg( requiredStorageB / 1024 / 1024 / 1024 );
     cDebug() << "Storage capacity  B:" << availableStorageB
              << QString( "(%1GB)" ).arg( availableStorageB / 1024 / 1024 / 1024 )
-             << "for" << candidate->partitionPath() << "   length:" << candidate->length();
+             << "for" << convenienceName( candidate ) << "   length:" << candidate->length();
 
     if ( ok &&
          availableStorageB > requiredStorageB )
     {
-        cDebug() << "Partition" << candidate->partitionPath() << "authorized for replace install.";
+        cDebug() << "Partition" << convenienceName( candidate ) << "authorized for replace install.";
 
         return true;
     }
@@ -85,7 +104,7 @@ canBeResized( Partition* candidate )
         return false;
     }
 
-    cDebug() << "Checking if" << candidate->partitionPath() << "can be resized.";
+    cDebug() << "Checking if" << convenienceName( candidate ) << "can be resized.";
     if ( !candidate->fileSystem().supportGrow() ||
          !candidate->fileSystem().supportShrink() )
     {
@@ -139,13 +158,13 @@ canBeResized( Partition* candidate )
              << QString( "(%1GB)" ).arg( advisedStorageGB );
     cDebug() << "Available storage B:" << availableStorageB
              << QString( "(%1GB)" ).arg( availableStorageB / 1024 / 1024 / 1024 )
-             << "for" << candidate->partitionPath() << "   length:" << candidate->length()
+             << "for" << convenienceName( candidate ) << "   length:" << candidate->length()
              << "   sectorsUsed:" << candidate->sectorsUsed() << "   fsType:" << candidate->fileSystem().name();
 
     if ( ok &&
          availableStorageB > advisedStorageB )
     {
-        cDebug() << "Partition" << candidate->partitionPath() << "authorized for resize + autopartition install.";
+        cDebug() << "Partition" << convenienceName( candidate ) << "authorized for resize + autopartition install.";
 
         return true;
     }
@@ -381,7 +400,7 @@ isEfiSystem()
 bool
 isEfiBootable( const Partition* candidate )
 {
-    cDebug() << "Check EFI bootable" << candidate->partitionPath() << candidate->devicePath();
+    cDebug() << "Check EFI bootable" << convenienceName( candidate ) << candidate->devicePath();
     cDebug() << " .. flags" << candidate->activeFlags();
 
     auto flags = PartitionInfo::flags( candidate );