Tools: Accept mAh as a unit

Tools/autotest/param_metadata/param.py

@@ -96,7 +96,7 @@ known_units = {
              'deg/m/s' : 'degrees per meter per second'  ,
              'm/s/m'   : 'meters per second per meter'   , # Why not use Hz here ????
              'mGauss/A': 'milligauss per ampere' ,
-             'mA.h'    : 'milliampere hour'      ,
+             'mAh'    : 'milliampere hour'      ,
              'A/V'     : 'ampere per volt'       ,
              'm/V'     : 'meters per volt'       ,
              'gravities': 'standard acceleration due to gravity' , # g_n would be a more correct unit, but IMHO no one understands what g_n means