USB: cxacru: Fix negative dB output

Values of dB between -0.99 and -0.01 will be output with the wrong
sign. This converts the negative value to positive and outputs it
with a "-" prefix.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/atm/cxacru.c b/drivers/usb/atm/cxacru.c
index 6789089..56802d2 100644
--- a/drivers/usb/atm/cxacru.c
+++ b/drivers/usb/atm/cxacru.c
@@ -227,8 +227,14 @@
 
 static ssize_t cxacru_sysfs_showattr_dB(s16 value, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d.%02u\n",
-					value / 100, abs(value) % 100);
+	if (likely(value >= 0)) {
+		return snprintf(buf, PAGE_SIZE, "%u.%02u\n",
+					value / 100, value % 100);
+	} else {
+		value = -value;
+		return snprintf(buf, PAGE_SIZE, "-%u.%02u\n",
+					value / 100, value % 100);
+	}
 }
 
 static ssize_t cxacru_sysfs_showattr_bool(u32 value, char *buf)