zephyr: remove trailing tab

Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/boot/zephyr/main.c b/boot/zephyr/main.c
index 2cb18b6..c141c43 100644
--- a/boot/zephyr/main.c
+++ b/boot/zephyr/main.c
@@ -49,7 +49,7 @@
 
 static inline bool boot_skip_serial_recovery()
 {
-#if NRF_POWER_HAS_RESETREAS	
+#if NRF_POWER_HAS_RESETREAS
     u32_t rr = nrf_power_resetreas_get(NRF_POWER);
 
     return !(rr == 0 || (rr & NRF_POWER_RESETREAS_RESETPIN_MASK));