staging: gpib: Remove unused value

staging: gpib: Remove unused value

The variable `complement_count` is assigned a value which is again
overwritten in the next statement.
Fix this by removing the first value assigning statement

This issue was reported by Coverity Scan.
Report:
CID 1600790: (#1 of 1): Unused value (UNUSED_VALUE)
assigned_value: Assigning value from length to complement_count here,
but that stored value is overwritten before it can be used.

Signed-off-by: Everest K.C. <everestkc@everestkc.com.np>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20241016075544.4125-1-everestkc@everestkc.com.np
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>