Make WARNS=2 build without error.

svn path=/head/; revision=121363

sbin/mount_msdosfs/Makefile

@@ -10,7 +10,7 @@ LDADD=	-lkiconv
 
 MOUNT=	${.CURDIR}/../mount
 CFLAGS+= -I${MOUNT}
-WARNS=	0
+WARNS=	2
 
 # Needs to be dynamically linked for optional dlopen() access to
 # userland libiconv

sbin/mount_msdosfs/mount_msdosfs.c

@@ -40,6 +40,7 @@ static const char rcsid[] =
 #include <sys/stat.h>
 #include <sys/module.h>
 #include <sys/iconv.h>
+#include <sys/linker.h>
 
 #include <fs/msdosfs/msdosfsmount.h>
 
@@ -55,7 +56,6 @@ static const char rcsid[] =
 #include <string.h>
 #include <sysexits.h>
 #include <unistd.h>
-
 #include "mntopts.h"
 
 #define TRANSITION_PERIOD_HACK