s390/vmlogrdr: Use array instead of string initializer

Compiling vmlogrdr with GCC 15 generates this warning:

  CC [M]  drivers/s390/char/vmlogrdr.o
drivers/s390/char/vmlogrdr.c:126:29: error: initializer-string for array
 of ‘char’ is too long [-Werror=unterminated-string-initialization]
  126 |         { .system_service = "*LOGREC ",

Given that the system_service array intentionally contains a non-null
terminated string use an array initializer, instead of string
initializer to get rid of this warning.

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

drivers/s390/char/vmlogrdr.c

@@ -123,7 +123,7 @@ static DECLARE_WAIT_QUEUE_HEAD(read_wait_queue);
  */
 
 static struct vmlogrdr_priv_t sys_ser[] = {
-	{ .system_service = "*LOGREC ",
+	{ .system_service = { '*', 'L', 'O', 'G', 'R', 'E', 'C', ' ' },
 	  .internal_name  = "logrec",
 	  .recording_name = "EREP",
 	  .minor_num      = 0,
@@ -132,7 +132,7 @@ static struct vmlogrdr_priv_t sys_ser[] = {
 	  .autorecording  = 1,
 	  .autopurge      = 1,
 	},
-	{ .system_service = "*ACCOUNT",
+	{ .system_service = { '*', 'A', 'C', 'C', 'O', 'U', 'N', 'T' },
 	  .internal_name  = "account",
 	  .recording_name = "ACCOUNT",
 	  .minor_num      = 1,
@@ -141,7 +141,7 @@ static struct vmlogrdr_priv_t sys_ser[] = {
 	  .autorecording  = 1,
 	  .autopurge      = 1,
 	},
-	{ .system_service = "*SYMPTOM",
+	{ .system_service = { '*', 'S', 'Y', 'M', 'P', 'T', 'O', 'M' },
 	  .internal_name  = "symptom",
 	  .recording_name = "SYMPTOM",
 	  .minor_num      = 2,