uml: rename pt_regs general-purpose register file

Before the removal of tt mode, access to a register on the skas-mode side of a
pt_regs struct looked like pt_regs.regs.skas.regs.regs[FOO].  This was bad
enough, but it became pt_regs.regs.regs.regs[FOO] with the removal of the
union from the middle.  To get rid of the run of three "regs", the last field
is renamed to "gp".

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 8582c13..50b476f 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -34,7 +34,7 @@
 		result = -ENOSYS;
 	else result = EXECUTE_SYSCALL(syscall, regs);
 
-	REGS_SET_SYSCALL_RETURN(r->regs, result);
+	REGS_SET_SYSCALL_RETURN(r->gp, result);
 
 	syscall_trace(r, 1);
 }