fs: Mark function as static in ext2/xattr_security.c

Mark function as static in ext2/xattr_security.c because it is not
used outside this file.

This also elimiantes the following warning in ext2/xattr_security.c:
fs/ext2/xattr_security.c:45:5: warning: no previous prototype for ‘ext2_initxattrs’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NJan Kara <jack@suse.cz>

fs/ext2/xattr_security.c

@@ -42,7 +42,7 @@ ext2_xattr_security_set(struct dentry *dentry, const char *name,
 			      value, size, flags);
 }
 
-int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+static int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
 			   void *fs_info)
 {
 	const struct xattr *xattr;