ssh: fixes for minor scan-build warnings

/usr/share/clang/scan-build/ccc-analyzer -DHAVE_CONFIG_H -I. -I..   -I./../libhtp/  -I/usr/include/nspr   -I/usr/include/nss -I/usr/include/nspr   -DLOCAL_STATE_DIR=\"/usr/local/var\" -g -O2 -Wall -Wno-unused-parameter -std=gnu99 -DHAVE_LIBNET11 -D_BSD_SOURCE -D__BSD_SOURCE -D__FAVOR_BSD -DHAVE_NET_ETHERNET_H -DHAVE_LIBNET_ICMPV6_UNREACH  -I/usr/include -DLIBPCAP_VERSION_MAJOR=1 -DHAVE_PCAP_SET_BUFF -DHAVE_LIBCAP_NG -DREVISION="51e0dee" -MT app-layer-ssh.o -MD -MP -MF .deps/app-layer-ssh.Tpo -c -o app-layer-ssh.o app-layer-ssh.c
app-layer-ssh.c:164:5: warning: Value stored to 'input' is never read
    input += 1;
    ^        ~
app-layer-ssh.c:165:5: warning: Value stored to 'input_len' is never read
    input_len -= 1;
    ^            ~
app-layer-ssh.c:212:13: warning: Value stored to 'ret' is never read
            ret = 0;
            ^     ~
3 warnings generated.

src/app-layer-ssh.c

@@ -131,7 +131,8 @@ static int SSHParseBanner(SshState *state, SshHeader *header, const uint8_t *inp
     SCReturnInt(len);
 }
 
-static int SSHParseRecordHeader(SshState *state, SshHeader *header, uint8_t *input, uint32_t input_len)
+static int SSHParseRecordHeader(SshState *state, SshHeader *header,
+        const uint8_t *input, uint32_t input_len)
 {
 #ifdef DEBUG
     BUG_ON(input_len != 6);
@@ -163,9 +164,6 @@ static int SSHParseRecordHeader(SshState *state, SshHeader *header, uint8_t *inp
 
     header->msg_code = *input;
 
-    input += 1;
-    input_len -= 1;
-
     SCLogDebug("msg code: %u", header->msg_code);
 
     if (header->msg_code == SSH_MSG_NEWKEYS) {
@@ -211,7 +209,6 @@ static int SSHParseRecord(SshState *state, SshHeader *header, uint8_t *input, ui
             SCLogDebug("Version string parsed, remaining length %d", ret);
             input += input_len - ret;
             input_len -= (input_len - ret);
-            ret = 0;
 
             uint32_t u = 0;
             while (u < input_len && (input[u] == '\r' || input[u] == '\n')) {