genconfig.py: only use CONFIG.local

Everything we need is in CONFIG.local - so just use that
file.  This allows us to remove the for loop as well.

CONFIG.local is currently a symlink to mk/config.mk - that
will be changed in the patch that removes the symlink.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Ia7f84eac85d322f2873f089ab62c99a69c4d9ef9

Reviewed-on: https://review.gerrithub.io/429947
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: GangCao <gang.cao@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>

scripts/genconfig.py

@@ -16,9 +16,8 @@ for arg in sys.argv:
         args[var] = val
 
 defs = {}
-for config in ('CONFIG', 'CONFIG.local'):
-    try:
-        with open(config) as f:
+try:
+    with open("CONFIG.local") as f:
         for line in f:
             line = line.strip()
             if not comment.match(line):
@@ -37,8 +36,8 @@ for config in ('CONFIG', 'CONFIG.local'):
                     else:
                         strval = val.replace('"', '\"')
                         defs["SPDK_{0}".format(var)] = strval
-    except IOError:
-        continue
+except IOError:
+    print("CONFIG.local not found")
 
 for key, value in sorted(defs.items()):
     if value == 0: