HDFFV-11096 replace backticks with doublequotes

tools/testfiles/pbits/tpbitsMaxExceeded.ddl

@@ -15,7 +15,7 @@ usage: h5dump [OPTIONS] files
      --s3-cred=<cred>     Supply S3 authentication information to "ros3" vfd.
                           <cred> :: "(<aws-region>,<access-id>,<access-key>)"
                           If absent or <cred> -> "(,,)", no authentication.
-                          Has no effect if filedriver is not `ros3'.
+                          Has no effect if filedriver is not "ros3".
      --hdfs-attrs=<attrs> Supply configuration information for HDFS file access.
                           For use with "--filedriver=hdfs"
                           <attrs> :: (<namenode name>,<namenode port>,
@@ -73,7 +73,7 @@ usage: h5dump [OPTIONS] files
      -D U, --xml-dtd=U    Use the DTD or schema at U
      -X S, --xml-ns=S     (XML Schema) Use qualified names n the XML
                           ":": no namespace, default: "hdf5:"
-                          E.g., to dump a file called `-f', use h5dump -- -f
+                          E.g., to dump a file called "-f", use h5dump -- -f
 
 --------------- Subsetting Options ---------------
  Subsetting is available by using the following options with a dataset