i2c: Fix error value returned by several bus drivers

When adding checks for ACPI resource conflicts to many bus drivers,
not enough attention was paid to the error paths, and for several
drivers this causes 0 to be returned on error in some cases. Fix this
by properly returning a non-zero value on every error.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org
diff --git a/drivers/i2c/busses/i2c-sis630.c b/drivers/i2c/busses/i2c-sis630.c
index e6f539e..b617fd0 100644
--- a/drivers/i2c/busses/i2c-sis630.c
+++ b/drivers/i2c/busses/i2c-sis630.c
@@ -393,7 +393,7 @@
 {
 	unsigned char b;
 	struct pci_dev *dummy = NULL;
-	int retval = -ENODEV, i;
+	int retval, i;
 
 	/* check for supported SiS devices */
 	for (i=0; supported[i] > 0 ; i++) {
@@ -418,18 +418,21 @@
 	*/
 	if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG,&b)) {
 		dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 	/* if ACPI already enabled , do nothing */
 	if (!(b & 0x80) &&
 	    pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
 		dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 
 	/* Determine the ACPI base address */
 	if (pci_read_config_word(sis630_dev,SIS630_ACPI_BASE_REG,&acpi_base)) {
 		dev_err(&sis630_dev->dev, "Error: Can't determine ACPI base address\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 
@@ -445,6 +448,7 @@
 			    sis630_driver.name)) {
 		dev_err(&sis630_dev->dev, "SMBus registers 0x%04x-0x%04x already "
 			"in use!\n", acpi_base + SMB_STS, acpi_base + SMB_SAA);
+		retval = -EBUSY;
 		goto exit;
 	}