backtrace: use namespace prefix osmo_*

Summary of changes:

s/backtrace/osmo_backtrace/g
diff --git a/include/osmocom/core/backtrace.h b/include/osmocom/core/backtrace.h
index bbbb2c2..5a8a816 100644
--- a/include/osmocom/core/backtrace.h
+++ b/include/osmocom/core/backtrace.h
@@ -1,6 +1,6 @@
 #ifndef _OSMO_BACKTRACE_H_
 #define _OSMO_BACKTRACE_H_
 
-void generate_backtrace();
+void osmo_generate_backtrace();
 
 #endif
diff --git a/src/backtrace.c b/src/backtrace.c
index ecd6b9c..8281fad 100644
--- a/src/backtrace.c
+++ b/src/backtrace.c
@@ -29,7 +29,7 @@
 
 #ifdef HAVE_EXECINFO_H
 #include <execinfo.h>
-void generate_backtrace()
+void osmo_generate_backtrace()
 {
 	int i, nptrs;
 	void *buffer[100];
diff --git a/src/panic.c b/src/panic.c
index 588a5fe..d445226 100644
--- a/src/panic.c
+++ b/src/panic.c
@@ -38,7 +38,7 @@
 static void osmo_panic_default(const char *fmt, va_list args)
 {
 	vfprintf(stderr, fmt, args);
-	generate_backtrace();
+	osmo_generate_backtrace();
 	abort();
 }