spi: bfin_spi: Remove unnecessary test for bus and pins[bus]

For invalid bus number, current code returns NULL in the default case of
switch-case statements. In additional, pins[bus] is always not NULL because
it is the address of specific row of the two-dimensional array.
Thus this patch removes these unnecessary test.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>

drivers/spi/bfin_spi.c

@@ -162,21 +162,22 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	if (!spi_cs_is_valid(bus, cs))
 		return NULL;
 
-	if (bus >= ARRAY_SIZE(pins) || pins[bus] == NULL) {
-		debug("%s: invalid bus %u\n", __func__, bus);
-		return NULL;
-	}
 	switch (bus) {
 #ifdef SPI0_CTL
-		case 0: mmr_base = SPI0_CTL; break;
+	case 0:
+		mmr_base = SPI0_CTL; break;
 #endif
 #ifdef SPI1_CTL
-		case 1: mmr_base = SPI1_CTL; break;
+	case 1:
+		mmr_base = SPI1_CTL; break;
 #endif
 #ifdef SPI2_CTL
-		case 2: mmr_base = SPI2_CTL; break;
+	case 2:
+		mmr_base = SPI2_CTL; break;
 #endif
-		default: return NULL;
+	default:
+		debug("%s: invalid bus %u\n", __func__, bus);
+		return NULL;
 	}
 
 	bss = spi_alloc_slave(struct bfin_spi_slave, bus, cs);