autobaud: Fix baud_changed undefined reference (#190)

src/autobaud.c

diff --git a/src/autobaud.c b/src/autobaud.c
index e5d61c1..f6316fb 100644
--- a/src/autobaud.c
+++ b/src/autobaud.c
@@ -194,7 +194,7 @@
 
 // Compare rounded integer parts of baud rates
 // Tolerance of 0.5% in detected versus set
-inline bool baud_changed(float new_baud, float baud) {
+static inline bool baud_changed(float new_baud, float baud) {
     uint32_t hi = (uint32_t)(baud * 1.005f);
     uint32_t lo = (uint32_t)(baud * 0.995f);
     uint32_t new = (uint32_t)new_baud;