fix wrong argument names

Author: wkliao

examples/get_info.py

@@ -52,7 +52,7 @@ def pnetcdf_io(filename):
     # create a new file using clobber "w" mode
     f = pnetcdf.File(filename=filename,
                      mode = 'w',
-                     file_format = "NC_64BIT_DATA",
+                     format = "NC_64BIT_DATA",
                      comm=comm,
                      info=None)
 

test/tst_file_mode.py

@@ -58,7 +58,7 @@ def tearDown(self):
     def runTest(self):
         """testing file access with different modes with CDF5/CDF2/CDF1 file format"""
         # TEST MODE "w"
-        with pnetcdf.File(filename=self.file_path, mode='w', format=self.file_format, Comm=comm) as f:
+        with pnetcdf.File(filename=self.file_path, mode='w', format=self.file_format, comm=comm) as f:
         # Try writing to file by defining a dimension
             f.def_dim('x',xdim)
         # Validate the created data file using ncvalidator tool