package/util-linux: make wipefs depend on BR2_USE_MMU

It depends on libblkid and libsmartcols, which use fork().

Fixes:
  http://autobuild.buildroot.net/results/82f9712bc90377c625caeb5b175e83a03d5b9d75/

Signed-off-by: Carlos Santos <unixmania@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit d83b5d628a79e21485eb6445ba9526075675e195)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/util-linux/Config.in

@@ -409,6 +409,7 @@ config BR2_PACKAGE_UTIL_LINUX_WALL
 
 config BR2_PACKAGE_UTIL_LINUX_WIPEFS
 	bool "wipefs"
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_UTIL_LINUX_LIBBLKID
 	select BR2_PACKAGE_UTIL_LINUX_LIBSMARTCOLS
 	help