utils: use namespace prefix osmo_*

Summary of changes:

s/bcd2char/osmo_bcd2char/g
s/char2bcd/osmo_char2bcd/g
s/hexparse/osmo_hexparse/g
s/hexdump/osmo_hexdump/g
s/hexdump_nospc/osmo_hexdump_nospc/g
s/ubit_dump/osmo_ubit_dump/g
s/static_assert/osmo_static_assert/g
diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 57b5d7f..8665c2b 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -181,7 +181,7 @@
 static inline struct msgb *msgb_alloc_headroom(int size, int headroom,
 						const char *name)
 {
-	static_assert(size > headroom, headroom_bigger);
+	osmo_static_assert(size > headroom, headroom_bigger);
 
 	struct msgb *msg = msgb_alloc(size, name);
 	if (msg)