[PATCH net-next v2] net: Remove redundant variable declaration in __dev_change_flags()

[Breno Leitao]

The old_flags variable is declared twice in __dev_change_flags(),
causing a shadow variable warning. This patch fixes the issue by
removing the redundant declaration, reusing the existing old_flags
variable instead.

	net/core/dev.c:9225:16: warning: declaration shadows a local variable [-Wshadow]
	9225 |                 unsigned int old_flags = dev->flags;
	|                              ^
	net/core/dev.c:9185:15: note: previous declaration is here
	9185 |         unsigned int old_flags = dev->flags;
	|                      ^
	1 warning generated.

Remove the redundant inner declaration and reuse the existing old_flags
variable since its value is not needed outside the if block, and it is
safe to reuse the variable. This eliminates the warning while
maintaining the same functionality.

Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@xxxxxxxxx>
---
Changes in v2:
- Improve the commit message to specify that there is no impact reusing
  the variable (Andrew)
- Remove the Fixes tag, since we do not want this to be backported.
  (Andrew)
- Link to v1: https://lore.kernel.org/r/20250214-old_flags-v1-1-29096b9399a9@xxxxxxxxxx
---
 net/core/dev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index d5ab9a4b318ea4926c200ef20dae01eaafa18c6b..cd2474a138201e6ee86acf39ca425d57d8d2e9b4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9182,7 +9182,7 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags,
 
 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
-		unsigned int old_flags = dev->flags;
+		old_flags = dev->flags;
 
 		dev->gflags ^= IFF_PROMISC;
 

---
base-commit: 7a7e0197133d18cfd9931e7d3a842d0f5730223f
change-id: 20250214-old_flags-528fe052471c

Best regards,
-- 
Breno Leitao <leitao@xxxxxxxxxx>