Rename isfinite to is_finite to avoid name conflicts.

matrix/helper_functions.hpp

@@ -14,7 +14,7 @@ namespace matrix
 {
 
 template<typename Type>
-bool isfinite(Type x) {
+bool is_finite(Type x) {
 #if defined (__PX4_NUTTX) || defined (__PX4_QURT)
     return PX4_ISFINITE(x);
 #else
@@ -25,7 +25,7 @@ bool isfinite(Type x) {
 template<typename Type>
 Type wrap_pi(Type x)
 {
-    if (!isfinite(x)) {
+    if (!is_finite(x)) {
         return x;
     }