Removed /system/bin prefix from gdbclient.

Now a program run through gdbclient will not automatically have
/system/bin added to its path, so programs not in /system/bin will no
longer need to be prefixed with ../../.

The following now works as an example:
 adb shell gdbserver :5039 /system/xbin/crasher
 bg
 gdbclient /system/xbin/crasher :5039 /system/xbin/crasher

And the following now no longer works:
 adb shell gdbserver :5039 /system/xbin/crasher
 bg
 gdbclient ../../system/xbin/crasher :5039 /system/xbin/crasher

Change-Id: I299b66d03915aeb1dc300e43a81c9a51f0bd7dec