UML - Fix boot crash

My copying of linux/init.h didn't go far enough.  The definition of
__used singled out gcc minor version 3, but didn't care what the major
version was.  This broke when unit-at-a-time was added and gcc started
throwing out initcalls.

This results in an early boot crash when ptrace tries to initialize a
process with an empty, uninitialized register set.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/include/init.h b/arch/um/include/init.h
index b00a957..37dd097 100644
--- a/arch/um/include/init.h
+++ b/arch/um/include/init.h
@@ -45,6 +45,8 @@
 # define __section(S) __attribute__ ((__section__(#S)))
 #endif
 
+#if __GNUC__ == 3
+
 #if __GNUC_MINOR__ >= 3
 # define __used			__attribute__((__used__))
 #else
@@ -52,6 +54,12 @@
 #endif
 
 #else
+#if __GNUC__ == 4
+# define __used			__attribute__((__used__))
+#endif
+#endif
+
+#else
 #include <linux/compiler.h>
 #endif
 /* These are for everybody (although not all archs will actually