MIPS: Octeon: board_type_to_string: return NULL for unsupported board

Return NULL for unsupported board.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12581/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/cavium-octeon/setup.c

@@ -466,9 +466,14 @@ static char __read_mostly octeon_system_type[80];
 
 static int __init init_octeon_system_type(void)
 {
+	char const *board_type;
+
+	board_type = cvmx_board_type_to_string(octeon_bootinfo->board_type);
+	if (board_type == NULL)
+		board_type = "Unsupported Board";
+
 	snprintf(octeon_system_type, sizeof(octeon_system_type), "%s (%s)",
-		cvmx_board_type_to_string(octeon_bootinfo->board_type),
-		octeon_model_get_string(read_c0_prid()));
+		 board_type, octeon_model_get_string(read_c0_prid()));
 
 	return 0;
 }

arch/mips/include/asm/octeon/cvmx-bootinfo.h

@@ -400,7 +400,7 @@ static inline const char *cvmx_board_type_to_string(enum
 		ENUM_BRD_TYPE_CASE(CVMX_BOARD_TYPE_KONTRON_S1901)
 		ENUM_BRD_TYPE_CASE(CVMX_BOARD_TYPE_CUST_PRIVATE_MAX)
 	}
-	return "Unsupported Board";
+	return NULL;
 }
 
 #define ENUM_CHIP_TYPE_CASE(x) \