util: audit: 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/viraudit.c

@@ -97,7 +97,7 @@ void virAuditSend(virLogSourcePtr source,
                   virAuditRecordType type ATTRIBUTE_UNUSED, bool success,
                   const char *fmt, ...)
 {
-    char *str = NULL;
+    VIR_AUTOFREE(char *) str = NULL;
     va_list args;
 
     /* Duplicate later checks, to short circuit & avoid printf overhead
@@ -144,7 +144,6 @@ void virAuditSend(virLogSourcePtr source,
         }
     }
 #endif
-    VIR_FREE(str);
 }
 
 void virAuditClose(void)