gdbclient: Improve error handling
gdbclient: Improve error handling

  Print error message when unable to resolve exefile by pid

Change-Id: I5d04bdc348e5f95818ac90e29148947edfce42eb

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build