Documentation/driver-api: firmware/firmware_cache: drop doubled word

Drop the doubled word "if".

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: [e-mail]
Acked-by: Luis Chamberlain <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/driver-api/firmware/firmware_cache.rst

···
   uses all synchronous call except :c:func:`request_firmware_into_buf`.
 
 * If an asynchronous call is used the firmware cache is only set up for a
-  device if if the second argument (uevent) to request_firmware_nowait() is
+  device if the second argument (uevent) to request_firmware_nowait() is
   true. When uevent is true it requests that a kobject uevent be sent to
   userspace for the firmware request through the sysfs fallback mechanism
   if the firmware file is not found.