Fix makefiles in samples

samples/1_Utils/hipBusBandwidth/Makefile

@@ -1,4 +1,7 @@
-HIP_PATH?=../../..
+HIP_PATH?= $(wildcard /opt/rocm/hip)
+ifeq (,$(HIP_PATH))
+	HIP_PATH=../../..
+endif
 HIPCC=$(HIP_PATH)/bin/hipcc
 
 EXE=hipBusBandwidth

samples/1_Utils/hipDispatchLatency/Makefile

@@ -1,4 +1,7 @@
-HIP_PATH?=../../..
+HIP_PATH?= $(wildcard /opt/rocm/hip)
+ifeq (,$(HIP_PATH))
+	HIP_PATH=../../..
+endif
 HIPCC=$(HIP_PATH)/bin/hipcc
 
 EXE=hipDispatchLatency

samples/1_Utils/hipInfo/Makefile

@@ -1,4 +1,7 @@
-HIP_PATH?=../../..
+HIP_PATH?= $(wildcard /opt/rocm/hip)
+ifeq (,$(HIP_PATH))
+	HIP_PATH=../../..
+endif
 HIPCC=$(HIP_PATH)/bin/hipcc
 
 EXE=hipInfo