[CVE-2009-0029] Convert all system calls to return a long

Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/mm/mremap.c b/mm/mremap.c
index 646de95..5572e08 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -420,7 +420,7 @@
 	return ret;
 }
 
-asmlinkage unsigned long sys_mremap(unsigned long addr,
+asmlinkage long sys_mremap(unsigned long addr,
 	unsigned long old_len, unsigned long new_len,
 	unsigned long flags, unsigned long new_addr)
 {