efibc: Report more information in the error messages

efibc: Report more information in the error messages

Report the name of the EFI variable if the value size is too large,
or if efibc_set_variable() fails to allocate the 'struct efivar_entry'
object.

If efibc_set_variable() fails because the 'size' value is too
large, it also reports this value in the error message.

Reported-by: Robert Elliott <[email protected]>
Signed-off-by: Jeremy Compostella <[email protected]>
Signed-off-by: Matt Fleming <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <[email protected]>