[scripts] Print full clang prebuilt dir from get_clang_version.py

e.g. clang-r416183b1 instead of just r416183b1.

Test: manually run the script
Change-Id: I993202ea97433f841e3127ecef46dec66fb9a8c9

scripts/get_clang_version.py

@@ -30,7 +30,7 @@ def get_clang_prebuilts_version(global_go):
   with open(global_go) as infile:
     contents = infile.read()
 
-  regex_rev = r'\tClangDefaultVersion\s+= "clang-(?P<rev>r\d+[a-z]?\d?)"'
+  regex_rev = r'\tClangDefaultVersion\s+= "(?P<rev>clang-r\d+[a-z]?\d?)"'
   match_rev = re.search(regex_rev, contents)
   if match_rev is None:
     raise RuntimeError('Parsing clang info failed')