perf tools: Fix maps__find_symbol_by_name()

perf tools: Fix maps__find_symbol_by_name()

Commit 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry
trampolines") revealed a problem with maps__find_symbol_by_name() that
resulted in probes not being found e.g.

	$ sudo perf probe xsk_mmap
	xsk_mmap is out of .text, skip it.
	Probe point 'xsk_mmap' not found.
	   Error: Failed to add events.

maps__find_symbol_by_name() can optionally return the map of the found
symbol. It can get the map wrong because, in fact, the symbol is found
on the map's dso, not allowing for the possibility that the dso has more
than one map. Fix by always checking the map contains the symbol.

Reported-by: Björn Töpel <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Björn Töpel <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: [email protected]
Fixes: 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry trampolines")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>