mount.cifs: fix bad free() of string returned by dirname()

Coverity says:

  Error: CPPCHECK_WARNING: [#def10]
  cifs-utils-6.2/mount.cifs.c:1518: error[memleakOnRealloc]: Common realloc mistake: 'mtabdir' nulled but not freed upon failure

del_mtab has a number of bugs in handling of allocated memory:

a) the return value of strdup() is not checked

b) It calls realloc() on a pointer that wasn't returned by an allocation
   function (e.g. malloc, calloc, etc.)

c) If realloc() fails, it doesn't call free() on the original memory
   returned by strdup()

Fix all of these bugs and add newlines to the end of the error messages
in del_mtab.

Signed-off-by: Jeff Layton <jlayton@samba.org>

0 files changed, 0 insertions, 0 deletions