Enable variadic checks for rpmExpand(), rpmlog() and rpmGetPath()

Suggested by Michal Marek

rpmio/rpmfileutil.h

@@ -6,6 +6,7 @@
  * File and path manipulation helper functions.
  */
 
+#include <rpm/rpmutil.h>
 #include <rpm/rpmio.h>
 #include <rpm/rpmpgp.h>
 
@@ -83,7 +84,7 @@ char * rpmGenPath	(const char * urlroot,
  * @param path		macro(s) to expand (NULL terminates list)
  * @return		canonicalized path (malloc'ed)
  */
-char * rpmGetPath (const char * path, ...);
+char * rpmGetPath (const char * path, ...) RPM_GNUC_NULL_TERMINATED;
 
 /** \ingroup rpmfileutil
  * Return URL path(s) from a (URL prefixed) pattern glob.

rpmio/rpmlog.h

@@ -10,6 +10,8 @@
 #include <stdarg.h>
 #include <stdio.h>
 
+#include <rpm/rpmutil.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -220,7 +222,7 @@ int rpmlogSetMask (int mask);
 /** \ingroup rpmlog
  * Generate a log message using FMT string and option arguments.
  */
-void rpmlog (int code, const char *fmt, ...);
+void rpmlog (int code, const char *fmt, ...) RPM_GNUC_PRINTF(2, 3);
 
 /** \ingroup rpmlog
  * Return text of last rpmError() message.

rpmio/rpmmacro.h

@@ -8,6 +8,8 @@
 #include <stdio.h>
 #include <stddef.h>
 
+#include <rpm/rpmutil.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -124,7 +126,7 @@ void	rpmFreeMacros	(rpmMacroContext mc);
  * @param arg		macro(s) to expand (NULL terminates list)
  * @return		macro expansion (malloc'ed)
  */
-char * rpmExpand	(const char * arg, ...);
+char * rpmExpand	(const char * arg, ...) RPM_GNUC_NULL_TERMINATED;
 
 /** \ingroup rpmmacro
  * Return macro expansion as a numeric value.