iwlwifi: mvm: fix typo in WARNING in rs.c
iwlwifi: mvm: fix typo in WARNING in rs.c

The current WARNING isn't very helpful.

Reported-by: David Binderman <b6d239d25020cc5e235b79047ed71f02d7363ad6@hotmail.com>
Signed-off-by: Emmanuel Grumbach <643a80aaf16a8332d6a70921c14d4bb265446494@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs