Various clang tidy warning fixes (#448)

* Fixed clang-tidy bugprone-reserved-identifier warnings

* Fixed clang-tidy bugprone-assert-side-effect warnings

* Fixed clang-tidy bugprone-copy-constructor-init warning

* Fixed clang-tidy readability-redundant-preprocessor warning

For error_test.c the removed code was already dead, because it was in the else of an `#if H5_USE_16_API` block.

Based on H5Location.h, I think p_get_ref_obj_type was meant to be in `#ifndef DOXYGEN_SHOULD_SKIP_THIS` and an `#endif` was missing.  Similarly, in the header, getObjTypeByIdx is only in H5_NO_DEPRECATED_SYMBOLS, not DOXYGEN_SHOULD_SKIP_THIS.

* Fixed clang-tidy readability-redundant-string-init warnings

* Fixed some clang-tidy performance-type-promotion-in-math-fn warnings

* Fixed clang-tidy performance-unnecessary-value-param warnings

* Reformat source with clang v10.0.1.

Co-authored-by: Larry Knox <lrknox@hdfgroup.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/tools/test/perform/sio_engine.c b/tools/test/perform/sio_engine.c
index f8061d4..e5a0ec8 100644
--- a/tools/test/perform/sio_engine.c
+++ b/tools/test/perform/sio_engine.c
@@ -80,7 +80,7 @@ static int clean_file_g = -1; /*whether to cleanup temporary test     */
 /*0 is no cleanup; 1 is do cleanup      */
 
 /* the different types of file descriptors we can expect */
-typedef union _file_descr {
+typedef union {
     int   posixfd; /* POSIX file handle*/
     hid_t h5fd;    /* HDF5 file        */
 } file_descr;
diff --git a/tools/test/perform/sio_perf.c b/tools/test/perform/sio_perf.c
index 8463ffa..5b3a9e8 100644
--- a/tools/test/perform/sio_perf.c
+++ b/tools/test/perform/sio_perf.c
@@ -292,7 +292,7 @@ struct options {
     size_t      page_size;
 };
 
-typedef struct _minmax {
+typedef struct {
     double min;
     double max;
     double sum;