[PATCH] disallow modular BINFMT_ELF

From: Adrian Bunk <bunk@fs.tum.de>

Modular BINFMT_ELF doesn't build, and is pretty pathological anyway.

So just make it a boolean rather than a tristate.

fs/Kconfig.binfmt

 config BINFMT_ELF
-	tristate "Kernel support for ELF binaries"
+	bool "Kernel support for ELF binaries"
 	depends on MMU
 	default y
 	---help---