Minor fixes to help texts

It's not true (anymore?) that the number of SCM jobs for gclient sync equals the
number of cores, thus the new text is less specific.

BUG=none

Review URL: https://codereview.chromium.org/184733007

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@254242 0039d316-1c4b-4281-b951-d872f2087c98

gclient.py

@@ -1661,7 +1661,7 @@ def CMDsync(parser, args):
                          '--force, such dependencies are removed even if they '
                          'have local modifications. When used with --reset, '
                          'all untracked directories are removed from the '
-                         'working copy, exclusing those which are explicitly '
+                         'working copy, excluding those which are explicitly '
                          'ignored in the repository.')
   parser.add_option('-R', '--reset', action='store_true',
                     help='resets any local changes before updating (git only)')
@@ -1835,7 +1835,7 @@ class OptionParser(optparse.OptionParser):
     self.add_option(
         '-j', '--jobs', default=jobs, type='int',
         help='Specify how many SCM commands can run in parallel; defaults to '
-             'number of cpu cores (%default)')
+             '%default on this machine')
     self.add_option(
         '-v', '--verbose', action='count', default=0,
         help='Produces additional output for diagnostics. Can be used up to '