bnge: use int for bnge_fix_rings_count() return value

bnge: use int for bnge_fix_rings_count() return value

bnge_fix_rings_count() returns 0 on success or a negative errno on failure
However, bnge_adjust_rings() stores its return value in a u16 variable,
causing negative error codes such as -ENOMEM to be converted to a large
positive value.

Use an int for the return code variable so that error values are
preserved and propagated correctly.

Fixes: 627c67f038d2 ("bng_en: Add resource management support")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Bhargava Marreddy <bhargava.marreddy@broadcom.com>
Link: https://patch.msgid.link/20260801100923.1498570-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>