[PATCH] fix qla{2,4} build error

commit 0181944f adds a
'extended_error_logging' global variable to qla2xxx which is defined by
qla4xxx too.

Trying to build both drivers results in the following error:

  LD      drivers/scsi/built-in.o
  drivers/scsi/qla4xxx/built-in.o: In function `qla4xxx_slave_configure':
  drivers/scsi/qla4xxx/ql4_os.c:1433: multiple definition of `extended_error_logging'
  drivers/scsi/qla2xxx/built-in.o:drivers/scsi/qla2xxx/qla_os.c:2166:
  first defined here
  make[2]: *** [drivers/scsi/built-in.o] Error 1
  make[1]: *** [drivers/scsi] Error 2
  make: *** [drivers] Error 2

The following patch simply adds a qla2_ (qla4_ respectively) prefix to
the variable name.

Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>