[PATCH] uml: compile fixes for gcc 4

This is a bunch of compile fixes provoked by building UML with gcc 4.  There
are a bunch of signedness mismatches, a couple of uninitialized references,
and a botched C99 structure initialization which had somehow gone unnoticed.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/drivers/slip_proto.h b/arch/um/drivers/slip_proto.h
index 7206361..4c4d94a 100644
--- a/arch/um/drivers/slip_proto.h
+++ b/arch/um/drivers/slip_proto.h
@@ -12,7 +12,8 @@
 #define SLIP_ESC_END         0334	/* ESC ESC_END means END 'data'	*/
 #define SLIP_ESC_ESC         0335	/* ESC ESC_ESC means ESC 'data'	*/
 
-static inline int slip_unesc(unsigned char c,char *buf,int *pos, int *esc)
+static inline int slip_unesc(unsigned char c, unsigned char *buf, int *pos,
+                             int *esc)
 {
 	int ret;