[PATCH -next] counter: fix Documentation build error due to incorrect source file name

[Randy Dunlap]

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Fix kernel-doc build error in Documentation/driver-api/generic-counter.rst
of incorrect source file name.
Fixes this warning and error:

Error: Cannot open file ../drivers/counter/generic-counter.c
WARNING: kernel-doc '../scripts/kernel-doc -rst -enable-lineno -export ../drivers/counter/generic-counter.c' failed with return code 2

Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
Cc: linux-iio@xxxxxxxxxxxxxxx
---
 Documentation/driver-api/generic-counter.rst |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20190517.orig/Documentation/driver-api/generic-counter.rst
+++ linux-next-20190517/Documentation/driver-api/generic-counter.rst
@@ -251,7 +251,7 @@ for defining a counter device.
 .. kernel-doc:: include/linux/counter.h
    :internal:
 
-.. kernel-doc:: drivers/counter/generic-counter.c
+.. kernel-doc:: drivers/counter/counter.c
    :export:
 
 Implementation