util: iohelper: use VIR_AUTOFREE instead of VIR_FREE for scalar types

By making use of GNU C's cleanup attribute handled by the
VIR_AUTOFREE macro for declaring scalar variables, majority
of the VIR_FREE calls can be dropped, which in turn leads to
getting rid of most of our cleanup sections.

Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

src/util/iohelper.c

@@ -46,7 +46,7 @@
 static int
 runIO(const char *path, int fd, int oflags)
 {
-    void *base = NULL; /* Location to be freed */
+    VIR_AUTOFREE(void *) base = NULL; /* Location to be freed */
     char *buf = NULL; /* Aligned location within base */
     size_t buflen = 1024*1024;
     intptr_t alignMask = 64*1024 - 1;
@@ -174,8 +174,6 @@ runIO(const char *path, int fd, int oflags)
         virReportSystemError(errno, _("Unable to close %s"), path);
         ret = -1;
     }
-
-    VIR_FREE(base);
     return ret;
 }