treewide: remove current_text_addr

Prefer _THIS_IP_ defined in linux/kernel.h.

Most definitions of current_text_addr were the same as _THIS_IP_, but
a few archs had inline assembly instead.

This patch removes the final call site of current_text_addr, making all
of the definitions dead code.

[akpm@linux-foundation.org: fix arch/csky/include/asm/processor.h]
Link: http://lkml.kernel.org/r/20180911182413.180715-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/h8300/include/asm/processor.h

@@ -12,12 +12,6 @@
 #ifndef __ASM_H8300_PROCESSOR_H
 #define __ASM_H8300_PROCESSOR_H
 
-/*
- * Default implementation of macro that returns current
- * instruction pointer ("program counter").
- */
-#define current_text_addr() ({ __label__ _l; _l: &&_l; })
-
 #include <linux/compiler.h>
 #include <asm/segment.h>
 #include <asm/ptrace.h>