iwlwifi: fw: make pos static in iwl_sar_get_ewrd_table() loop

In the for loop where we are supposed to go through the entire table,
we are using a non-static local to keep the pos index.  This makes
each iteration start with 3, so we always access the first item on the
table.  Fix this by moving the variable outside of the loo so it
doesn't lose its value at every iteration.

Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Fixes: ba3224db ("iwlwifi: mvm: fix an out-of-bound access")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>