print-interpreter: fix off by one error

Fix off by one error in the code that reads interpreter from the ELF
file. This was not evident when it was written directly to STDOUT but
became problematic through my exploration of new functionality (NixOS#357)
since there was an additional '\0' and the strings would not concatenate
as a result.

.gitignore

@@ -32,3 +32,7 @@ Makefile
 /tests/libbig-dynstr.debug
 /tests/contiguous-note-sections
 /tests/simple-pie
+
+.direnv/
+.vscode/
+.idea/

src/patchelf.cc

@@ -1237,7 +1237,7 @@ template<ElfFileParams>
 std::string ElfFile<ElfFileParamNames>::getInterpreter()
 {
     auto shdr = findSection(".interp");
-    return std::string((char *) fileContents->data() + rdi(shdr.sh_offset), rdi(shdr.sh_size));
+    return std::string((char *) fileContents->data() + rdi(shdr.sh_offset), rdi(shdr.sh_size) - 1);
 }
 
 template<ElfFileParams>