QASMBench has comments after instructions

QASMBench has lines that have comments after instructions, and those lines cause errors.
This fix remove such comments.

src/qutip_qip/qasm.py

@@ -886,7 +886,15 @@ def read_qasm(qasm_input, mode="qiskit", version="2.0", strmode=False):
     # split input into lines and ignore comments
     qasm_lines = [line.strip() for line in qasm_lines]
     qasm_lines = list(filter(lambda x: x[:2] != "//" and x != "", qasm_lines))
-
+    # QASMBench Benchmark Suite has lines that have comments after instructions.
+    # Not sure if QASM standard allows this.
+    for i in range(len(qasm_lines)):
+       qasm_line = qasm_lines[i]
+       loc_comment = qasm_line.find("//")
+       if loc_comment >= 0:
+          qasm_line = qasm_line[0:loc_comment]
+       qasm_lines[i] = qasm_line
+
     if version != "2.0":
         raise NotImplementedError(
             "QASM: Only OpenQASM 2.0 \