ShellPkg/UefiShellAcpiViewCommandLib: Fix ECC issues

1. Separate variable definition and initialization.
2. Make the variable naming following Edk2 rule.

V2: Remove the updates of guard macros in header files.

Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Evan Lloyd <evan.lloyd@arm.com>
Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

ShellPkg/Library/UefiShellAcpiViewCommandLib/AcpiView.h

@@ -33,11 +33,11 @@
   The EREPORT_OPTION enum describes ACPI table Reporting options.
 **/
 typedef enum ReportOption {
-  EREPORT_ALL,            ///< Report All tables.
-  EREPORT_SELECTED,       ///< Report Selected table.
-  EREPORT_TABLE_LIST,     ///< Report List of tables.
-  EREPORT_DUMP_BIN_FILE,  ///< Dump selected table to a file.
-  EREPORT_MAX
+  ReportAll,            ///< Report All tables.
+  ReportSelected,       ///< Report Selected table.
+  ReportTableList,      ///< Report List of tables.
+  ReportDumpBinFile,    ///< Dump selected table to a file.
+  ReportMax,
 } EREPORT_OPTION;
 
 /**