ftrace: rename FTRACE to FUNCTION_TRACER

Due to confusion between the ftrace infrastructure and the gcc profiling
tracer "ftrace", this patch renames the config options from FTRACE to
FUNCTION_TRACER.  The other two names that are offspring from FTRACE
DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same.

This patch was generated mostly by script, and partially by hand.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Makefile b/Makefile
index 16e3fbb..b7eb70b 100644
--- a/Makefile
+++ b/Makefile
@@ -536,7 +536,7 @@
 KBUILD_AFLAGS	+= -gdwarf-2
 endif
 
-ifdef CONFIG_FTRACE
+ifdef CONFIG_FUNCTION_TRACER
 KBUILD_CFLAGS	+= -pg
 endif