net/ice/base: refactor zeroing bitmap size

net/ice/base: refactor zeroing bitmap size

A couple of places in the code use a 'sizeof(bitmap) * BITS_PER_BYTE'
construction to calculate the size of the bitmap when calling
ice_zero_bitmap. Instead of doing this, just use the same value as in
the ice_declare_bitmap declaration.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Leyi Rong <leyi.rong@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>