net: qed: fix "maybe uninitialized" warning

Variable 'abs_ppfid' in qed_dev.c:qed_llh_add_mac_filter() always gets
printed, but is initialized only under 'ref_cnt == 1' condition. This
results in:

In file included from ./include/linux/kernel.h:15:0,
                 from ./include/asm-generic/bug.h:19,
                 from ./arch/x86/include/asm/bug.h:86,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/io.h:11,
                 from drivers/net/ethernet/qlogic/qed/qed_dev.c:35:
drivers/net/ethernet/qlogic/qed/qed_dev.c: In function 'qed_llh_add_mac_filter':
./include/linux/printk.h:358:2: warning: 'abs_ppfid' may be used uninitialized
in this function [-Wmaybe-uninitialized]
  printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
  ^~~~~~
drivers/net/ethernet/qlogic/qed/qed_dev.c:983:17: note: 'abs_ppfid' was declared
here
  u8 filter_idx, abs_ppfid;
                 ^~~~~~~~~

...under W=1+.

Fix this by initializing it with zero.

Fixes: 79284ade ("qed: Add llh ppfid interface and 100g support for offload protocols")
Signed-off-by: Alexander Lobakin <alobakin@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_dev.c

@@ -980,7 +980,7 @@ int qed_llh_add_mac_filter(struct qed_dev *cdev,
 	struct qed_hwfn *p_hwfn = QED_LEADING_HWFN(cdev);
 	struct qed_ptt *p_ptt = qed_ptt_acquire(p_hwfn);
 	union qed_llh_filter filter = {};
-	u8 filter_idx, abs_ppfid;
+	u8 filter_idx, abs_ppfid = 0;
 	u32 high, low, ref_cnt;
 	int rc = 0;