lib/, libsubid/, po/, src/: get_gid(): Move function to "atoi/getnum.h"

Implement it as an inline function, and add restrict and ATTR_STRING()
and ATTR_ACCESS() as appropriate.

Reviewed-by: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

src/groupadd.c

@@ -23,6 +23,8 @@
 #include <pwd.h>
 #endif				/* USE_PAM */
 #endif				/* ACCT_TOOLS_SETUID */
+
+#include "atoi/getnum.h"
 #include "chkname.h"
 #include "defines.h"
 #include "getdef.h"
@@ -37,6 +39,7 @@
 #include "shadowlog.h"
 #include "run_part.h"
 
+
 /*
  * exit status values
  */

src/groupmod.c

@@ -27,6 +27,7 @@
 #endif				/* ACCT_TOOLS_SETUID */
 
 #include "alloc.h"
+#include "atoi/getnum.h"
 #include "chkname.h"
 #include "defines.h"
 #include "groupio.h"
@@ -40,6 +41,8 @@
 #include "shadowlog.h"
 #include "string/stpecpy.h"
 #include "string/stpeprintf.h"
+
+
 /*
  * exit status values
  */

src/newusers.c

@@ -31,6 +31,7 @@
 #include <string.h>
 
 #include "alloc.h"
+#include "atoi/getnum.h"
 #include "atoi/str2i.h"
 #ifdef ACCT_TOOLS_SETUID
 #ifdef USE_PAM