Add _buf() functions to bypass static string buffers

We have a number of static buffers in use in libosmo*.  This means
the related functions are not usable in a thread-safe way.  While
we so far don't have many multi-threaded programs in the osmocom
universe, the static buffers also prevent us from calling the same
e.g. string-ify function twice within a single printf() call.

Let's make sure there's an alternative function in all those cases,
where the user can pass in a caller-allocated buffer + size, and make
the 'classic' function with the static buffer a wrapper around that
_buf() variant.

Change-Id: Ibf85f79e93244f53b2684ff6f1095c5b41203e05
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index e3728cd..6a2b7d5 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -53,6 +53,7 @@
 
 int osmo_hexparse(const char *str, uint8_t *b, int max_len);
 
+char *osmo_ubit_dump_buf(char *buf, size_t buf_len, const uint8_t *bits, unsigned int len);
 char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);
 char *osmo_hexdump(const unsigned char *buf, int len);
 char *osmo_hexdump_nospc(const unsigned char *buf, int len);
@@ -139,7 +140,7 @@
 const char *osmo_escape_str(const char *str, int len);
 char *osmo_escape_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
 const char *osmo_quote_str(const char *str, int in_len);
-const char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
+char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
 
 uint32_t osmo_isqrt32(uint32_t x);