msm: ipa: bug fix in adding flt_rule

bug fix in case a flt rule is requested to be added
by Q6 through equation.

Change-Id: I337abd48add8f7f3a09afe3db93c5fbdfe009da6
Acked-by: Yaniv Hasbani <yhasbani@qti.qualcomm.com>
Signed-off-by: Talel Shenhar <tatias@codeaurora.org>