kfifo: add missing MODULE_DESCRIPTION() macros

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/kfifo/bytestream-example.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/kfifo/dma-example.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/kfifo/inttype-example.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/kfifo/record-example.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Link: https://lkml.kernel.org/r/20240601-md-samples-kfifo-v1-1-de34345c5fd8@quicinc.com
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: jeff-t-johnson

samples/kfifo/bytestream-example.c

@@ -191,5 +191,6 @@ static void __exit example_exit(void)
 
 module_init(example_init);
 module_exit(example_exit);
+MODULE_DESCRIPTION("Sample kfifo byte stream implementation");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");

samples/kfifo/dma-example.c

@@ -138,5 +138,6 @@ static void __exit example_exit(void)
 
 module_init(example_init);
 module_exit(example_exit);
+MODULE_DESCRIPTION("Sample fifo dma implementation");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");

samples/kfifo/inttype-example.c

@@ -182,5 +182,6 @@ static void __exit example_exit(void)
 
 module_init(example_init);
 module_exit(example_exit);
+MODULE_DESCRIPTION("Sample kfifo int type implementation");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");

samples/kfifo/record-example.c

@@ -198,5 +198,6 @@ static void __exit example_exit(void)
 
 module_init(example_init);
 module_exit(example_exit);
+MODULE_DESCRIPTION("Sample dynamic sized record fifo implementation");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>");