perf symbols: Do not open device files

perf symbols: Do not open device files

The dso__read_binary_type_filename gets the dso's file name to open. We
need to check it for regular file before trying to open it, otherwise we
might get stuck with device file.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: Joe Mario <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/20160920161245.GA8995@krava
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>