linux: Get exe name from main arguments
linux: Get exe name from main arguments

When building in chromium, the test is linked into the crashpad_tests
target instead of crashpad_util_test.

Change-Id: I4e0f6b9956f191ebac10f0aaa3812e30885a4e0a
Reviewed-on: https://chromium-review.googlesource.com/1131688
Commit-Queue: Joshua Peraza <f5809a5e35ec7e1bd0e25cb0a0b68bb433cf6f17@chromium.org>
Reviewed-by: Robert Sesek <f55ad94e336f3a28322d0a25d280221ea9daf7a3@chromium.org>

chromium/crashpad,chromium/crashpad,chromium/crashpad