scsi: elx: libefc: Prefer kcalloc() over open coded arithmetic

As noted in the "Deprecated Interfaces, Language Features, Attributes, and
Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead to
values wrapping around and a smaller allocation being made than the caller
was expecting. Using those allocations could lead to linear overflows of
heap memory and other misbehaviors.

Use the purpose specific kcalloc() function instead of the argument count *
size in the kzalloc() function.

[1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Link: https://lore.kernel.org/r/20210905062448.6587-1-len.baker@gmx.com


Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Len Baker <len.baker@gmx.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>