fix BEGIN probe due to uninitialized loc

src/bpftrace.cpp

@@ -32,6 +32,7 @@ int BPFtrace::add_probe(ast::Probe &p)
       probe.type = probetype(attach_point->provider);
       probe.orig_name = p.name();
       probe.name = p.name();
+      probe.loc = 0;
       special_probes_.push_back(probe);
       continue;
     }
@@ -43,6 +44,7 @@ int BPFtrace::add_probe(ast::Probe &p)
       probe.type = probetype(attach_point->provider);
       probe.orig_name = p.name();
       probe.name = p.name();
+      probe.loc = 0;
       special_probes_.push_back(probe);
       continue;
     }
@@ -86,6 +88,7 @@ int BPFtrace::add_probe(ast::Probe &p)
       probe.orig_name = p.name();
       probe.name = attach_point->name(func);
       probe.freq = attach_point->freq;
+      probe.loc = 0;
       probes_.push_back(probe);
     }
   }

src/types.h

@@ -77,7 +77,7 @@ public:
   std::string orig_name;	// original full probe name,
 				// before wildcard expansion
   std::string name;		// full probe name
-  uint64_t loc;
+  uint64_t loc;			// for USDT probes
   int freq;
 };