sw:vec: Fix float_to_str error log with LOG_ERROR

Allows the function to be used without simprint (non-springbok config)
where libc_nano is used.

Change-Id: Id025fd49d2569c894913dd73e5c990184f8f64a7

springbok/springbok.cpp

diff --git a/springbok/springbok.cpp b/springbok/springbok.cpp
index 95c3941..514eda0 100644
--- a/springbok/springbok.cpp
+++ b/springbok/springbok.cpp
@@ -109,7 +109,8 @@
 extern "C" int float_to_str(const int len, char *buffer, const float value) {
   if (buffer == NULL && len != 0) {
     // Bad inputs
-    springbok_simprint(SPRINGBOK_SIMPRINT_ERROR, "float_to_str handed null buffer with non-zero length! len:", len);
+    LOG_ERROR("float_to_str handed null buffer with non-zero length! len:%d",
+              len);
     return 0;
   }