Kprobes: Make kprobe.symbol_name const

Kprobes doesn't scribble the kprobe.symbol_name field.  Its only set by the
module when registering the probe.  Modules that exercise good hygiene
using the "const" qualifier will see warnings...

	warning: assignment discards qualifiers from pointer target type

Make struct kprobe.symbol_name const char *

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/kprobes.h

@@ -78,7 +78,7 @@ struct kprobe {
 	kprobe_opcode_t *addr;
 
 	/* Allow user to indicate symbol name of the probe point */
-	char *symbol_name;
+	const char *symbol_name;
 
 	/* Offset into the symbol */
 	unsigned int offset;