i5100_edac: Remove two checkpatch warnings

The last changeset introduced a few checkpatch warnings:

WARNING: debugfs_remove_recursive(NULL) is safe this check is probably not required
261: FILE: drivers/edac/i5100_edac.c:1207:
+       if (priv->debugfs)
+               debugfs_remove_recursive(priv->debugfs);

WARNING: debugfs_remove(NULL) is safe this check is probably not required
290: FILE: drivers/edac/i5100_edac.c:1250:
+       if (i5100_debugfs)
+               debugfs_remove(i5100_debugfs);

Get rid of them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>