perf/probes: Improve probe point syntax of perf-probe

perf/probes: Improve probe point syntax of perf-probe

This changes probe point syntax of perf-probe as below

 <SRC>[:ABS_LN] [ARGS]
 or
 <FUNC>[+OFFS|%return][@SRC] [ARGS]

And event name and event group name are automatically
generated based on probe-symbol and offset as below.

 perfprobes/SYMBOL_OFFSET[_NUM]

Where SYMBOL is the probing symbol and OFFSET is
the byte offset from the symbol.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
LKML-Reference: <20091027204310.30545.84984.stgit@harusame>
Signed-off-by: Ingo Molnar <mingo@elte.hu>