tracing: Fix recordmcount.pl to handle sections with only weak functions

Roland Dreier found that a section that contained only a weak
function in one of the staging drivers and this caused
recordmcount.pl to spit out a warning and fail.

Although it is strange that a driver would have a weak function, and
this function only be used in one place, it should not be something
to make recordmcount.pl fail.

This patch fixes the issue in a simple manner: if only weak
functions exist in a section, then that section will not be
recorded.

Reported-by: Roland Dreier <[e-mail]>
Signed-off-by: Steven Rostedt <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

scripts/recordmcount.pl

···
 	    $read_function = 0;
 	}
 	# print out any recorded offsets
-	update_funcs() if ($text_found);
+	update_funcs() if (defined($ref_func));
 
 	# reset all markers and arrays
 	$text_found = 0;
···
 }
 
 # dump out anymore offsets that may have been found
-update_funcs() if ($text_found);
+update_funcs() if (defined($ref_func));
 
 # If we did not find any mcount callers, we are done (do nothing).
 if (!$opened) {