Let dumpstate die a normal death when receiving a singal

Having dumpstate not generate a crash report / tombstone makes
diagnosing crashes a bit harder. This change avoids calling _exit(3)
when receiving a signal, except for SIGPIPE which we just SIG_IGN.

Bug: 76120715
Test: dumpstate
Change-Id: I7bd986251f7174de77bdcfd4ff3ee26a1ef4afc7
1 file changed