dma-debug: fix return value of __setup handlers

When valid kernel command line parameters
dma_debug=off dma_debug_entries=100
are used, they are reported as Unknown parameters and added to init's
environment strings, polluting it.

Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5
dma_debug=off dma_debug_entries=100", will be passed to user space.

and

Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc5
dma_debug=off
dma_debug_entries=100

Return 1 from these __setup handlers to indicate that the command line
option has been handled.

Fixes: 59d3daafa1726 ("dma-debug: add kernel command line parameters")
Signed-off-by: Randy Dunlap <[e-mail]>
Reported-by: Igor Zhbanov <[e-mail]>
Link: lore.kernel.org/r/[e-mail]
Cc: Joerg Roedel <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Marek Szyprowski <[e-mail]>
Cc: [e-mail]
Cc: Robin Murphy <[e-mail]>
Signed-off-by: Christoph Hellwig <[e-mail]>

kernel/dma/debug.c

···
 		global_disable = true;
 	}
 
-	return 0;
+	return 1;
 }
 
 static __init int dma_debug_entries_cmdline(char *str)
···
 		return -EINVAL;
 	if (!get_option(&str, &nr_prealloc_entries))
 		nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
-	return 0;
+	return 1;
 }
 
 __setup("dma_debug=", dma_debug_cmdline);