qemuimage-testlib-pythonhelper: Fix process mixups

runqemu-internal runs "ldd qemu-system xxx" and the detection code was returning this
as the PID of qemu. This patch improves the detection code to avoid this problem,
fixing certain race type failures on the autobuilder.

(From OE-Core rev: fc914a6fb3204f8b5bdfc0f56364606673d5356a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/qemuimage-testlib-pythonhelper

@@ -3,6 +3,7 @@
 import optparse
 import subprocess
 import sys
+import os
 
 parser = optparse.OptionParser(
     usage = """
@@ -52,7 +53,10 @@ if options.findqemu:
         newparents = next
     #print "Children matching %s:" % str(parents)
     for p in parents:
-        if "qemu-system" in commands[p]:
+        # Need to be careful here since runqemu-internal runs "ldd qemu-system-xxxx"
+        basecmd = commands[p].split()[0]
+        basecmd = os.path.basename(basecmd)
+        if "qemu-system" in basecmd:
             print p
             sys.exit(0)
     sys.exit(1)