Fix inline functions to use 'static inline'

With just 'inline', if the compiler decides not to inline them, it isn't
required to emit them at all. For some targets with -Os that is causing
build failures, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86360.

Perhaps we might consider using '__attribute__((always_inline))' for
GCC builds, but 'static inline' is a good start.

Signed-off-by: Steve Markgraf <steve@steve-m.de>

src/rtl_adsb.c

@@ -183,7 +183,7 @@ int magnitute(uint8_t *buf, int len)
 	return len/2;
 }
 
-inline uint16_t single_manchester(uint16_t a, uint16_t b, uint16_t c, uint16_t d)
+static inline uint16_t single_manchester(uint16_t a, uint16_t b, uint16_t c, uint16_t d)
 /* takes 4 consecutive real samples, return 0 or 1, BADSAMPLE on error */
 {
 	int bit, bit_p;
@@ -224,17 +224,17 @@ inline uint16_t single_manchester(uint16_t a, uint16_t b, uint16_t c, uint16_t d
 	return BADSAMPLE;
 }
 
-inline uint16_t min16(uint16_t a, uint16_t b)
+static inline uint16_t min16(uint16_t a, uint16_t b)
 {
 	return a<b ? a : b;
 }
 
-inline uint16_t max16(uint16_t a, uint16_t b)
+static inline uint16_t max16(uint16_t a, uint16_t b)
 {
 	return a>b ? a : b;
 }
 
-inline int preamble(uint16_t *buf, int i)
+static inline int preamble(uint16_t *buf, int i)
 /* returns 0/1 for preamble at index i */
 {
 	int i2;

src/rtl_power.c

@@ -250,7 +250,7 @@ void sine_table(int size)
 	}
 }
 
-inline int16_t FIX_MPY(int16_t a, int16_t b)
+static inline int16_t FIX_MPY(int16_t a, int16_t b)
 /* fixed point multiply and scale */
 {
 	int c = ((int)a * (int)b) >> 14;