test-runner: remove path_exists/find_binary

These are already implemented in the shutil module

tools/run-tests

@@ -57,28 +57,6 @@ def exit_vm():
 
 	runner.stop()
 
-def path_exists(path):
-	'''
-		Searches PATH as well as absolute paths.
-	'''
-	if shutil.which(path):
-		return True
-	try:
-		os.stat(path)
-	except:
-		return False
-	return True
-
-def find_binary(list):
-	'''
-		Returns a binary from 'list' if its found in PATH or on a
-		valid absolute path.
-	'''
-	for path in list:
-		if path_exists(path):
-			return path
-	return None
-
 class Interface:
 	def __init__(self, name, config):
 		self.name = name
@@ -529,7 +507,7 @@ class TestContext(Namespace):
 			os.environ['IWD_SIM_KEYS'] = sim_keys
 			return
 
-		if not find_binary(['ofonod']) or not find_binary(['phonesim']):
+		if not shutil.which('ofonod') or not shutil.which(['phonesim']):
 			print("Ofono or Phonesim not found, skipping test")
 			return